In my opinion, they all need to push forward a bit. We don't need to see Sadio and Firmino dropping into deep midfield all the time to get the ball.
Perhaps Fabinho as the deepest, number 6 player could unlock all of this, including Naby Keita. Get Fab in there, keeping it simple and passing forward and let Keita be that link man, going box to box. Fabinho, Keita, Henderson could be a brilliant midfield if both Naby and Hendo are giving freedom to get forward and unleash havoc.
I'm confident we will see more of Naby soon. We've been spoiled by Mo Salah; players don't just join Liverpool and triple their output from their old club while setting the world alight.
However look at the Ox and Andy Robertson, Klopp is simply brilliant at bedding players in, over TIME.